Dear Team. Our system are using 02 switch2960, 02 router2921(EHWIC-4ESG).We have 5 vlan on switch and router, we use HSRP and Spanning-tree. When i plug cable with green color (Fe0/0/0 and Fe0/2/0), The system was loop. IOS c2900-universalk9-mz.SPA.1...